Image-forming devices, such as printers and copiers, use a variety of media that have numerous characteristics, including, for example, size, shape, material composition, color, weight, texture, roughness, resistivity, thickness, stiffness, grain direction, chemical composition, and acidity, all of which affect print quality. Given the numerous characteristics which determine the type of media, there are a large number of media available and in use in the market today. Without knowing the particular characteristics of the specific media being used, the image-forming device, which is optimized to provide good print quality on most standard or low-quality media, compromises otherwise higher print quality when higher-quality media is used. Similarly, there are many different types of image-forming devices in use, such as, for example, printers, copiers, scanners, and facsimile machines, each of which are made by numerous different manufacturers incorporating varying operational parameters into the devices. Many of these image-forming devices also require special types of print media for adequate performance. Thus, it is desirable that the image-forming device recognize the type of media being used or loaded into the supply or input tray.
Most image-forming devices in current use rely on a user to provide or input information about the type of media being used via a printer control panel. However, this particular system also depends on the user to input new parameters each time the media type is changed for the setting to remain accurate. Additional inaccuracies are likely to occur when the image-forming device is programmed by multiple users.
With respect to the size of the media, several methods of conveying the dimensions of the print media loaded in a supply tray have been developed. In one such method, a unique set of trays configured to accommodate a particular size of media is provided, allowing loading specifically sized media. This approach disadvantageously increases the cost of the image-forming device by requiring molding of various sizes and configurations of trays. Additionally, the user must buy and store multiple trays needed to support the many media sizes used. An alternative approach uses media trays that can be configured for all of the various sizes of media. While this approach reduces manufacturing cost and the purchase and storage of multiple trays, the user must still input the size of media loaded in the tray. Furthermore, these approaches do not identify the characteristics of the media being used.
Various other approaches are known in the art. One such approach is the use of default settings in the image-forming device for all media types. This provides acceptable print quality on most standard media types, but does not provide good print quality on non-standard media, such as photo papers and transparencies. Another approach relates to the use of media detection sensors, where several sensor types (e.g., optical, weight, resistivity, and reflectance sensors) are used. While these sensors are able to characterize media on a page-by-page basis, they are expensive and are limited to higher-end commercial printers.
Another approach relies on manual entry of the paper type by the user via control panel buttons. As with other manual entry methods, this method is error prone and requires incorporation of control panels having 10-key numeric pads (or cumbersome entry with more limited key pads) on the image-forming device. Additionally, the user can be tempted to use the default settings instead of reading a code number and entering the same into the image-forming device.
Other approaches rely on the use of bar code readers. One approach uses bar code readers located inside of paper trays. However, use of bar code readers in each individual tray increase the cost of production and complicates the design of image-forming devices that use multiple optional paper trays. This approach also requires paper that must be specially packaged in a ream with a perforated end, which must be designed so as to expose the media without discarding the bar code on the ream wrapper. However, no paper manufacturer currently ships a ream wrapper having such a configuration. Also, this system requires that the bar code be located at specific locations on the ream wrapper in order to be read by the specially designed media tray. Unfortunately, the bar code placements on media vary between manufacturers.
Bar codes have also been printed directly on the face of the media at various locations. However, this particular method is only suitable for use on very expensive media due to the high expense created in printing identification information on each and every page of media. Alternatively, bar code information has been printed on the edge of the media. While this method can be quicker and less expensive than printing bar codes directly on the face of the media, the media manufacturer is still required to pre-print each media ream before the media can be used in an image-forming device having a bar code reader. Thus, the invention is limited to use of media from the limited number of suppliers that employ such bar code techniques.